The Host Defense Group of the Laboratory of Respiratory Biology, Division of Intramural Research, National Institute of Environmental Health Sciences, headed by Michael B. Fessler, MD now enters its sixth year at the NIEHS since inception. We have now published several manuscripts. Publications since the last annual report: 1) an report using proteomic analysis to profile the complement of acylated (fatty acid-modified) proteins in the macrophage, and then validating the role of acylation in function of one such protein, phospholipid scramblase 3 (Merrick BA et al., Mol Cell Proteomics 2011) 2) a collaborative publication reporting the human Toll like Receptors are target genes of the master transcription factor p53 (Menendez D et al., PLoS Genetics 2011). 3) a collaborative publication describing the role of the cholesterol transporter ATP Binding Cassette transporter A1 in control of inflammatory signaling by macrophages (Zhu X et al., J Lipid Research 2010). 4) a review article describing how the flow of lipids through the plasma membrane of macrophages controls their inflammatory signaling (Fessler MB and Parks JS, J Immunology 2011). Additional accomplishments since our last report include an invitated talk delivered by Dr. Fessler at the 2011 Gordon Research Conference on Atherosclerosis and at the Duke University Airway Biology Forum, as well as an invitation to speak at the Fall 2011 Pulmonary Research Group Symposium (Stowe, VT). Dr. Fessler also had notable roles at the 2011 American Thoracic International Conference, including organizing/chairing and speaking at a scientific symposium, chairing a poster discussion session, and acting as facilitator at two additional thematic poster sessions. In addition, Dr. Saiful Chowdhury, a postdoctoral fellow in Fessler laboatory, received a 2011 NIH Fellows Award for Research Excellence. Dr. Fessler and his fellow, Dr. Jim Aloor, also established a provisional patent application on a novel protein that shows potential as a regulator of inflammatory responses (Provisional Patent Application #61/443,491: Modulation of Lrch4 activity and Therapeutic Application Thereof (filed January 17, 2011;inventors: Michael B. Fessler, Jim J. Aloor)).